Oilless antifriction bearings



Oct. 13, 1959 L. A. RUNTON ETAL 2,908,535

` oILLEss ANTIFRICTION BEARINGS Filed oct. 24. 1957 o. In .n` lo ln- Inl'. s, y/lylfv/fawfvl ',PEYMBWPRYQV OP-M'av'f 5 #www#wfmwawn EM Lui @ADAis.

f im@.@mmagy ff vdi \wl \\1/ wil w A v ff Tffzo/v /5 /5 lb *i /5uNveN-rons LES/E A. PUN/V HfA/@Y Makro/M 4 ATTORNEY Unitcdtatc-Patent OoILLEss ANTIFRICIION BEARINGS Leslie A. Runton, Middle Haddam, and HenryC. Morton, Branford, Conn., assignors to The Russell ManufacturingCompany, Middletown, Conn., a corporation of Connecticut ApplicationOctober 24, l1957, Serial No. 692,1118

2 Claims. (Cl. 308-163) This invention relates to oilless, anti-frictionbearings for light duty operations such as conveyor rollers or the like.

An object is to provide a molded fabric bearing disc which canconveniently be stamped in 'any desired size from a molded fabric sheetand in which anti-friction material is exposed on its inner and outerperipheries.

Another object is to provide a bearing of the above type which resistscontamination by dirt or grit or by chemicals which may be encounteredduring use.

Other objects and advantages will be apparent as the nature of theinvention is more fully disclosed.

The nature of the invention will be better understood from the followingdescription, taken in connection with the accompanying drawing in whicha specific embodiment has been set forth for purposes of illustration.

In the drawing:

Fig. 1 is a diagrammatic view illustrating the weave of the fabricembodying the invention;

Fig. 2 is a perspective View of a molded fabric sheet from which thebearing discs are to be stamped;

Fig. 3 is a perspective view of a bearing disc; and

Fig. 4 is a detail view illustrating the bearing discs in use inconnection with -a roller shaft.

Referring to Fig. l the fabric is illustrated as having six plies offiller shots 10. The number of plies may vary according to the desiredthickness ofthe fabric. The tiller shots of each ply are shown as boundby a pair of chain warps 11 to form a woven ply. The yarns 10 and 11 maybe co-mposed of materials which are capable of being bonded by animpregnant, for example cotton, Daeron, rayon, Orlon, by themselves, ortwisted with continuous multillament Teon yarns.

The plies are bound together by binder warps 15 composed of multiflamentTeflon (tetrauoroethylene), or of cotton yarn twisted with multiiilamentTeflon. Teilen has a low coefficient of friction Varying inversely withpressure, substantially no cold ilow under pressure, and by itself isincapable of bonding to the usual impregnants. When twisted with cottonyarn as above, however, the resulting yam is readily bondable.

The binder warps 15 extend through all of the plies and over the iilleryarns 10 of the outer plies. Each binder 15 passes through the fabric inan inclined direction and advances by at least one ller shot at eachpassage. The binders of diiferent dents are staggered in that atransverse cut through the fabric at any point, such as long lines 16 or17 of Fig. 1, intersects and cuts through a plurality of such binders toleave exposed ends at lthe plane of cutting.

The fabric may be impregnated with a high strength phenolic bondingresin derived from the reaction product of phenol, cresol or |ahomologue with formaldehyde under controlled conditions. The mixture ispreheated to 2,908,535 Patented Oct. 13, 1959 ICC remove the solvent andthe resin content polymerized until a residual volatile content of 5% to7% isattained. The mixture is then molded under heat and pressure to theform of a ilat sheet 28 as shown inFig. 2. The conversion of the resininto a thermoset lform may be accomplished at a temperature of 300 F. to350 F. for from thirty to sixty minutes at pressures of 10 tons t0 tons,depending upon the area of the object being molded.

The molded fabric sheet 28 of Fig. 2 may be stamped or eut to form discs21 of Fig. 3 having inner and outer peripheral bearing surfaces in whichthe Teilon yarns are exposed. These discs 21 may be stacked to form abearing of the required thickness as illustrated in Fig. 4.

In Fig. 4 a roller 30 which may comprise a conveyor roll, is providedwith a shaft 31 which is journaled in bearing disc 21 in a housing 32.The discs 21 are positioned on the shaft 31 by a metal washer 3S andseal held by a split ring 36.

The discs 21 are floating so that inner and outer peripheral bearingsurfaces are provided, formed of the exposed ends of Teon yarn which arerenewed as the plastic wears away to expose additional ends. Such abearing requires no lubrication and due to the low adhesioncharacteristics of the Teilon will not pick up or accumulate dirt ordust. Teiion is inert to -most of the chemicals now in use and is notattacked or corroded thereby.

Sheet 28 may also be produced by incorporating a short flock, such as1/2 mm. or 11/2 mm. of Tellon ock in a molded resin such aspolyvinylchloride, epoxy resins or phenolic resins.

In the case of a liquid such as polyvinylchloride the liquid may beplaced in an open top mold the proper shape to form the sheet and theflock sprinkled over the surface of the liquid and worked into theliquid by combing or stirring. The mold may then be heated to thepolymerizing temperature for polyvinylchloride, i.e. 350 F. to 360 F.and immediately cooled to set the resin to solid form with the Teonflock embedded therein.

The epoxy resins are -thermosetting and may be applied to the mold inthe form of a molding powder. The Teflon flock is incorporated in themolding powder prior to curing. The mixture is cured by heating to theproper temperature to convert the resin into lthe form of a solid bodyin which the Teflon ilock is embedded. The body may also be composed ofa high strength phenolic bonding resin such as that above described. TheTeflon flock is mixed with the resin molding powder in the desiredproportion prior to setting. The mixture is then molded under heat andpressure as above described to form the sheet 28. The discs 2i may thenbe stamped from the sheet 28 as above described -to form bearing ringswith the Teon flock exposed on the inner and outer surfaces.

A rubber base may also be used by mixing the Tellon flock with thenatural or synthetic latex, drying and vulcanizing to cured form.

What is claimed is:

1. An oilless, antifriction bearing disc having an inner bearingperipheral surface and an outer peripheral surface, said disc comprisinga woven fabric molded in a bonding resin, said fabric comprising iaplurality of plies containing yarns capable of bonding to said resinbound together by yarns of tetrailuoroethylene, said tetrauoroethylenebinding yarns extending through said plies from outside surface tooutside surface thereof whereby both the inner and outer peripheralsurfaces have ends of tetrau'oroethylene yarn exposed from side edge toside edge of said peripheral surfaces.

`to ofutside surface thereof whereby both the inner and outer peripheralsurfaces have ends of tetraiiuoroethylene yarn exposed from side edge toside edge of said peripheral suraces.

References Cited in the le of this patent UNITED STATES PATENTS ColomboMay 27, 1952 Mildner June 10, 1952 Wightrnan June 10, 1952 Stoak Aug.30, 1955 White sept. 3, 1957 Warren Sept. 10, 1957 FOREIGN PATENTS GreatBritain May 25, 1955

1. AN OILLESS ANTIFRICTION BEARING DISE HAVING AN INNER BEARING PERIPHERAL SURFACE AND AN OUTER PERIPHERAL SUPFACE, SAID DISC COMPRISING A WOVEN FABRIC MLDED IN A BONDING RESIN, SAID FABRIC COMPRISING A PLURALITY OF PLIES CONTAINING YARNS CAPALBE OF BONDING TO SAID RESIN BOUND TOGETHER BY YARNS OF TETRAFLUOROETHYLEN AND TETRAUFLUOROETHYLENE BINDING YARNS EXTENDING THROUGH SAID PLIES FROM 